Handwritten signatures are commonly used in payment operations today to verify that a purchaser or sender of money is authorized to make a transaction. It is important to verify the identity of the person performing the operation. Handwritten signatures are generally used to do this. However, handwritten signatures can easily be forged and it is difficult to truly authenticate other technologies, including the entering of a personal identification number (PIN). Recently, electronic signatures have become more common, including entering a signature on a digital surface.
Authentication of a person requesting access typically comprises comparing a signature image with a pre-stored image. Signatures can be copied with relative ease thus requiring multi factor authentication such as passwords, PIN entry and/or biometric scanners, including fingerprint or retina scans to positively identify the user. Multi-factor authentication can be cumbersome and confusing, requiring equipment and remembering of passwords.
Various styli are known. Typically, a stylus serves in conjunction with a scribing surface that is configured to work with the corresponding stylus. Generally speaking, a stylus is typically a hand-held writing tool that often (but not exclusively) has a pencil-like elongated form factor and that includes at least one pointed end configured to interact with a scribing surface. Using a stylus as an input mechanism offers a variety of advantages over a fingertip including the opportunity for increased precision as well as an expression modality that accords with the user's own past experience with a pencil or pen.
Together with a display, a stylus can at least serve to cause the display of a so-called electronic-ink line that tracks and corresponds to movement of the stylus on the scribing surface. Such an input modality permits the user to enter text or to draw an image.
In some cases, a device might be locked and require a password. This can be done via text entry, PIN entry, or biometric authentication.
Existing stylus-based modalities do not necessarily meet the needs of all users for accessing the device since an additional mode of authenticating a user is often needed.